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Help with a circuit

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New Member
I am looking to make a circuit that gives power to one wire when it receives power from 2 wires. It cannot give power if there is only power from one of the two wires. The system will be run off of 12 volt and does not need to work with a high amperage. If you need anymore information just ask and i will do my best to answer any questions.



Well-Known Member
Most Helpful Member
two 12 volt relays.
Power 1 drives relay1 coil
Power 2 drives relay2 coil
Connect from 12 volts to relay1 contact (normally open) then in series to relay2 contacts (normally open) then to output.
The contacts in series will only conduct when both relays are driven.


1 Relay, Plus CMOS AND gate.

Or Diode logic AND gate


Well-Known Member
Most Helpful Member
One relay. Two supplies 12A and 12B.
+12a supply only drives the coil of the relay.
+12b supply passes through the coil's normally open contacts to putput.


Super Moderator
Depending on how much "power" you want to give, the logic gate might not work in your situation.
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